OEM Replacement Control Board, Carrier HK42FZ-Series, 325878-751. Low cost form, fit and functional replacement board for Carrier. Controls gas valve, ignitor, blower motor, inducer, humidifier and air cleaner. Microprocessor-based for precise timing. Functions with all 24 VAC thermostats. Designed for 100% gas shutoff in case of ignition failure. Twinning compatible with another ICM281 board. Reverse polarity protection. Secondary brownout voltage protection. Diagnostic fault codes (blinking LED) for simple troubleshooting. Also for for Carrier HK42FZ004/007/008/009/011/013/016/034.